Question { TCS, 27945 }

Why VCB and SF6 breakers to be used in HT used by cant ACB
of higher rating to be used for 11kv and 33kv.

Answer

According BIS,IEC standards in HT lines the Isc that current
is very highly making arc that arc is quenched by the SF6 or
vcb. If ACB has used the breaker contacts & cables are burn
out at Isc.so we used SF6 & vcb has used in HT lines for
safety purpose

Question { Sail, 7978 }

what is the main different between distribution transformer
and power transformer ?

Answer

POWER TRANSFORMER IS USED FOR BOOSTING PURPOSE IN SS.
DISTRIBUTION TRANSFORMER IS USED TO STEP DOWN OR UP TO
DISTRIBUTE THE POWER TO CONSUMER.

Question { TCS, 8486 }

WHAT IS THE DIFFERENCE B/W BUSHINGS AND INSULATORS?
WHAT IS THE CREEPAGE DISTANCE ?

Answer

1)Insulator is made up of ceramic material(peeingan)

2)Bushing is made up of rubber material
but both are used for insulation purpose depend by KV rating

Question { ABB, 10488 }

where AVR is connected in power plant.

Answer

used in RTCC PANEL and alternator excitation

Question { 3501 }

which type of material is used for making motor encloser

Answer

it is made up of cast iron

Question { 3338 }

the fuse is use for protection against overcurrent but at
normal condition it carry the rated current then how single
thin wire carry this current without melting

Answer

Because it depending up on the load current material melting
point & resistivity

explanation:In loads occurs short circuit(or) high starting
current the conductor(thin wire) temperature is increase for
that certain stage when the material reach that melting
point the conductor (thin wire) melt & disconnect the circuit.